#ifndef _WX_WXSTREAM_H__
#define _WX_WXSTREAM_H__

#include "wx/defs.h"

#if wxUSE_STREAMS

#include <stdio.h>
#include "wx/object.h"
#include "wx/string.h"
#include "wx/filefn.h"  // for wxFileOffset, wxInvalidOffset and wxSeekMode

class wxStreamBase;
class wxInputStream;
class wxOutputStream;

typedef wxInputStream& ( *__wxInputManip )( wxInputStream& );
typedef wxOutputStream& ( *__wxOutputManip )( wxOutputStream& );

wxOutputStream& wxEndL( wxOutputStream& o_stream );

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

enum wxStreamError {
  wxSTREAM_NO_ERROR = 0,      // stream is in good state
  wxSTREAM_EOF,               // EOF reached in Read() or similar
  wxSTREAM_WRITE_ERROR,       // generic write error
  wxSTREAM_READ_ERROR         // generic read error
};

const int wxEOF = -1;

// ============================================================================
// base stream classes: wxInputStream and wxOutputStream
// ============================================================================

// ---------------------------------------------------------------------------
// wxStreamBase: common (but non virtual!) base for all stream classes
// ---------------------------------------------------------------------------

class wxStreamBase {
  public:
    wxStreamBase();
    virtual ~wxStreamBase();

    // error testing
    wxStreamError GetLastError() const { return m_lasterror; }
    virtual bool IsOk() const { return GetLastError() == wxSTREAM_NO_ERROR; }
    bool operator!() const { return !IsOk(); }

    // reset the stream state
    void Reset() { m_lasterror = wxSTREAM_NO_ERROR; }

    // this doesn't make sense for all streams, always test its return value
    virtual size_t GetSize() const;
    virtual wxFileOffset GetLength() const { return wxInvalidOffset; }

    // returns true if the streams supports seeking to arbitrary offsets
    virtual bool IsSeekable() const { return false; }

  protected:
    virtual wxFileOffset OnSysSeek( wxFileOffset seek, wxSeekMode mode );
    virtual wxFileOffset OnSysTell() const;

    size_t m_lastcount;
    wxStreamError m_lasterror;

    friend class wxStreamBuffer;

    DECLARE_NO_COPY_CLASS( wxStreamBase )
};

// ----------------------------------------------------------------------------
// wxInputStream: base class for the input streams
// ----------------------------------------------------------------------------

class wxInputStream : public wxStreamBase {
  public:
    // ctor and dtor, nothing exciting
    wxInputStream();
    virtual ~wxInputStream();


    // IO functions
    // ------------

    // return a character from the stream without removing it, i.e. it will
    // still be returned by the next call to GetC()
    //
    // blocks until something appears in the stream if necessary, if nothing
    // ever does (i.e. EOF) LastRead() will return 0 (and the return value is
    // undefined), otherwise 1
    virtual char Peek();

    // return one byte from the stream, blocking until it appears if
    // necessary
    //
    // on success returns a value between 0 - 255, or wxEOF on EOF or error.
    int GetC();

    // read at most the given number of bytes from the stream
    //
    // there are 2 possible situations here: either there is nothing at all in
    // the stream right now in which case Read() blocks until something appears
    // (use CanRead() to avoid this) or there is already some data available in
    // the stream and then Read() doesn't block but returns just the data it
    // can read without waiting for more
    //
    // in any case, if there are not enough bytes in the stream right now,
    // LastRead() value will be less than size but greater than 0. If it is 0,
    // it means that EOF has been reached.
    virtual wxInputStream& Read( void *buffer, size_t size );

    // copy the entire contents of this stream into streamOut, stopping only
    // when EOF is reached or an error occurs
    wxInputStream& Read( wxOutputStream& streamOut );


    // status functions
    // ----------------

    // returns the number of bytes read by the last call to Read(), GetC() or
    // Peek()
    //
    // this should be used to discover whether that call succeeded in reading
    // all the requested data or not
    virtual size_t LastRead() const { return wxStreamBase::m_lastcount; }

    // returns true if some data is available in the stream right now, so that
    // calling Read() wouldn't block
    virtual bool CanRead() const;

    // is the stream at EOF?
    //
    // note that this cannot be really implemented for all streams and
    // CanRead() is more reliable than Eof()
    virtual bool Eof() const;


    // write back buffer
    // -----------------

    // put back the specified number of bytes into the stream, they will be
    // fetched by the next call to the read functions
    //
    // returns the number of bytes really stuffed back
    size_t Ungetch( const void *buffer, size_t size );

    // put back the specified character in the stream
    //
    // returns true if ok, false on error
    bool Ungetch( char c );


    // position functions
    // ------------------

    // move the stream pointer to the given position (if the stream supports
    // it)
    //
    // returns wxInvalidOffset on error
    virtual wxFileOffset SeekI( wxFileOffset pos, wxSeekMode mode = wxFromStart );

    // return the current position of the stream pointer or wxInvalidOffset
    virtual wxFileOffset TellI() const;


    // stream-like operators
    // ---------------------

    wxInputStream& operator>>( wxOutputStream& out ) { return Read( out ); }
    wxInputStream& operator>>( __wxInputManip func ) { return func( *this ); }

  protected:
    // do read up to size bytes of data into the provided buffer
    //
    // this method should return 0 if EOF has been reached or an error occurred
    // (m_lasterror should be set accordingly as well) or the number of bytes
    // read
    virtual size_t OnSysRead( void *buffer, size_t size ) = 0;

    // write-back buffer support
    // -------------------------

    // return the pointer to a buffer big enough to hold sizeNeeded bytes
    char *AllocSpaceWBack( size_t sizeNeeded );

    // read up to size data from the write back buffer, return the number of
    // bytes read
    size_t GetWBack( void *buf, size_t size );

    // write back buffer or NULL if none
    char *m_wback;

    // the size of the buffer
    size_t m_wbacksize;

    // the current position in the buffer
    size_t m_wbackcur;

    friend class wxStreamBuffer;

    DECLARE_NO_COPY_CLASS( wxInputStream )
};

// ----------------------------------------------------------------------------
// wxOutputStream: base for the output streams
// ----------------------------------------------------------------------------

class wxOutputStream : public wxStreamBase {
  public:
    wxOutputStream();
    virtual ~wxOutputStream();

    void PutC( char c );
    virtual wxOutputStream& Write( const void *buffer, size_t size );
    wxOutputStream& Write( wxInputStream& stream_in );

    virtual wxFileOffset SeekO( wxFileOffset pos, wxSeekMode mode = wxFromStart );
    virtual wxFileOffset TellO() const;

    virtual size_t LastWrite() const { return wxStreamBase::m_lastcount; }

    virtual void Sync();
    virtual bool Close() { return true; }

    wxOutputStream& operator<<( wxInputStream& out ) { return Write( out ); }
    wxOutputStream& operator<<( __wxOutputManip func ) { return func( *this ); }

  protected:
    // to be implemented in the derived classes (it should have been pure
    // virtual)
    virtual size_t OnSysWrite( const void *buffer, size_t bufsize );

    friend class wxStreamBuffer;

    DECLARE_NO_COPY_CLASS( wxOutputStream )
};

// ============================================================================
// helper stream classes
// ============================================================================

// ---------------------------------------------------------------------------
// A stream for measuring streamed output
// ---------------------------------------------------------------------------

class wxCountingOutputStream : public wxOutputStream {
  public:
    wxCountingOutputStream();

    wxFileOffset GetLength() const;
    bool Ok() const { return IsOk(); }
    bool IsOk() const { return true; }

  protected:
    virtual size_t OnSysWrite( const void *buffer, size_t size );
    virtual wxFileOffset OnSysSeek( wxFileOffset pos, wxSeekMode mode );
    virtual wxFileOffset OnSysTell() const;

    size_t m_currentPos;

    DECLARE_NO_COPY_CLASS( wxCountingOutputStream )
};

// ---------------------------------------------------------------------------
// "Filter" streams
// ---------------------------------------------------------------------------

class wxFilterInputStream : public wxInputStream {
  public:
    wxFilterInputStream();
    wxFilterInputStream( wxInputStream& stream );
    wxFilterInputStream( wxInputStream *stream );
    virtual ~wxFilterInputStream();

    char Peek() { return m_parent_i_stream->Peek(); }

    wxFileOffset GetLength() const { return m_parent_i_stream->GetLength(); }

    wxInputStream *GetFilterInputStream() const { return m_parent_i_stream; }

  protected:
    wxInputStream *m_parent_i_stream;
    bool m_owns;

    DECLARE_NO_COPY_CLASS( wxFilterInputStream )
};

class wxFilterOutputStream : public wxOutputStream {
  public:
    wxFilterOutputStream();
    wxFilterOutputStream( wxOutputStream& stream );
    wxFilterOutputStream( wxOutputStream *stream );
    virtual ~wxFilterOutputStream();

    wxFileOffset GetLength() const { return m_parent_o_stream->GetLength(); }

    wxOutputStream *GetFilterOutputStream() const { return m_parent_o_stream; }

    bool Close();

  protected:
    wxOutputStream *m_parent_o_stream;
    bool m_owns;

    DECLARE_NO_COPY_CLASS( wxFilterOutputStream )
};

enum wxStreamProtocolType {
  wxSTREAM_PROTOCOL,  // wxFileSystem protocol (should be only one)
  wxSTREAM_MIMETYPE,  // MIME types the stream handles
  wxSTREAM_ENCODING,  // The HTTP Content-Encodings the stream handles
  wxSTREAM_FILEEXT    // File extensions the stream handles
};

void wxUseFilterClasses();

class wxFilterClassFactoryBase : public wxObject {
  public:
    virtual ~wxFilterClassFactoryBase() { }

    wxString GetProtocol() const { return wxString( *GetProtocols() ); }
    wxString PopExtension( const wxString& location ) const;

    virtual const wxChar * const *GetProtocols( wxStreamProtocolType type
        = wxSTREAM_PROTOCOL ) const = 0;

    bool CanHandle( const wxChar *protocol,
                    wxStreamProtocolType type
                    = wxSTREAM_PROTOCOL ) const;

  protected:
    wxString::size_type FindExtension( const wxChar *location ) const;

    DECLARE_ABSTRACT_CLASS( wxFilterClassFactoryBase )
};

class wxFilterClassFactory : public wxFilterClassFactoryBase {
  public:
    virtual ~wxFilterClassFactory() { }

    virtual wxFilterInputStream  *NewStream( wxInputStream& stream )  const = 0;
    virtual wxFilterOutputStream *NewStream( wxOutputStream& stream ) const = 0;
    virtual wxFilterInputStream  *NewStream( wxInputStream *stream )  const = 0;
    virtual wxFilterOutputStream *NewStream( wxOutputStream *stream ) const = 0;

    static const wxFilterClassFactory *Find( const wxChar *protocol,
        wxStreamProtocolType type
        = wxSTREAM_PROTOCOL );

    static const wxFilterClassFactory *GetFirst();
    const wxFilterClassFactory *GetNext() const { return m_next; }

    void PushFront() { Remove(); m_next = sm_first; sm_first = this; }
    void Remove();

  protected:
    wxFilterClassFactory() : m_next( this ) { }

    wxFilterClassFactory& operator=( const wxFilterClassFactory& ) { return *this; }

  private:
    static wxFilterClassFactory *sm_first;
    wxFilterClassFactory *m_next;

    DECLARE_ABSTRACT_CLASS( wxFilterClassFactory )
};

// ============================================================================
// buffered streams
// ============================================================================

// ---------------------------------------------------------------------------
// Stream buffer: this class can be derived from and passed to
// wxBufferedStreams to implement custom buffering
// ---------------------------------------------------------------------------

class wxStreamBuffer {
  public:
    enum BufMode {
      read,
      write,
      read_write
    };

    wxStreamBuffer( wxStreamBase& stream, BufMode mode );
    wxStreamBuffer( const wxStreamBuffer& buf );
    virtual ~wxStreamBuffer();

    // Filtered IO
    virtual size_t Read( void *buffer, size_t size );
    size_t Read( wxStreamBuffer *buf );
    virtual size_t Write( const void *buffer, size_t size );
    size_t Write( wxStreamBuffer *buf );

    virtual char Peek();
    virtual char GetChar();
    virtual void PutChar( char c );
    virtual wxFileOffset Tell() const;
    virtual wxFileOffset Seek( wxFileOffset pos, wxSeekMode mode );

    // Buffer control
    void ResetBuffer();

    // NB: the buffer must always be allocated with malloc() if takeOwn is
    //     true as it will be deallocated by free()
    void SetBufferIO( void *start, void *end, bool takeOwnership = false );
    void SetBufferIO( void *start, size_t len, bool takeOwnership = false );
    void SetBufferIO( size_t bufsize );
    void *GetBufferStart() const { return m_buffer_start; }
    void *GetBufferEnd() const { return m_buffer_end; }
    void *GetBufferPos() const { return m_buffer_pos; }
    size_t GetBufferSize() const { return m_buffer_size; }
    size_t GetIntPosition() const { return m_buffer_pos - m_buffer_start; }
    void SetIntPosition( size_t pos ) { m_buffer_pos = m_buffer_start + pos; }
    size_t GetLastAccess() const { return m_buffer_end - m_buffer_start; }
    size_t GetBytesLeft() const { return m_buffer_end - m_buffer_pos; }

    void Fixed( bool fixed ) { m_fixed = fixed; }
    void Flushable( bool f ) { m_flushable = f; }

    bool FlushBuffer();
    bool FillBuffer();
    size_t GetDataLeft();

    // misc accessors
    wxStreamBase *GetStream() const { return m_stream; }
    bool HasBuffer() const { return m_buffer_size != 0; }

    bool IsFixed() const { return m_fixed; }
    bool IsFlushable() const { return m_flushable; }

    // only for input/output buffers respectively, returns NULL otherwise
    wxInputStream *GetInputStream() const;
    wxOutputStream *GetOutputStream() const;
    wxDEPRECATED( wxStreamBase *Stream() );
    // this constructs a dummy wxStreamBuffer, used by (and exists for)
    // wxMemoryStreams only, don't use!
    wxStreamBuffer( BufMode mode );

  protected:
    void GetFromBuffer( void *buffer, size_t size );
    void PutToBuffer( const void *buffer, size_t size );

    // set the last error to the specified value if we didn't have it before
    void SetError( wxStreamError err );

    // common part of several ctors
    void Init();

    // init buffer variables to be empty
    void InitBuffer();

    // free the buffer (always safe to call)
    void FreeBuffer();

    // the buffer itself: the pointers to its start and end and the current
    // position in the buffer
    char *m_buffer_start,
         *m_buffer_end,
         *m_buffer_pos;
    size_t m_buffer_size;

    // the stream we're associated with
    wxStreamBase *m_stream;

    // its mode
    BufMode m_mode;

    // flags
    bool m_destroybuf,      // deallocate buffer?
         m_fixed,
         m_flushable;

  private:
    // Cannot use
    //  DECLARE_NO_COPY_CLASS(wxStreamBuffer)
    // because copy constructor is explicitly declared above;
    // but no copy assignment operator is defined, so declare
    // it private to prevent the compiler from defining it:
    wxStreamBuffer& operator=( const wxStreamBuffer& );
};

// ---------------------------------------------------------------------------
// wxBufferedInputStream
// ---------------------------------------------------------------------------

class wxBufferedInputStream : public wxFilterInputStream {
  public:
    // if a non NULL buffer is given to the stream, it will be deleted by it
    wxBufferedInputStream( wxInputStream& stream,
                           wxStreamBuffer *buffer = NULL );
    virtual ~wxBufferedInputStream();

    char Peek();
    wxInputStream& Read( void *buffer, size_t size );

    // Position functions
    wxFileOffset SeekI( wxFileOffset pos, wxSeekMode mode = wxFromStart );
    wxFileOffset TellI() const;
    bool IsSeekable() const { return m_parent_i_stream->IsSeekable(); }

    // the buffer given to the stream will be deleted by it
    void SetInputStreamBuffer( wxStreamBuffer *buffer );
    wxStreamBuffer *GetInputStreamBuffer() const { return m_i_streambuf; }
    wxDEPRECATED( wxStreamBuffer *InputStreamBuffer() const );
  protected:
    virtual size_t OnSysRead( void *buffer, size_t bufsize );
    virtual wxFileOffset OnSysSeek( wxFileOffset seek, wxSeekMode mode );
    virtual wxFileOffset OnSysTell() const;

    wxStreamBuffer *m_i_streambuf;

    DECLARE_NO_COPY_CLASS( wxBufferedInputStream )
};

// ----------------------------------------------------------------------------
// wxBufferedOutputStream
// ----------------------------------------------------------------------------

class wxBufferedOutputStream : public wxFilterOutputStream {
  public:
    // if a non NULL buffer is given to the stream, it will be deleted by it
    wxBufferedOutputStream( wxOutputStream& stream,
                            wxStreamBuffer *buffer = NULL );
    virtual ~wxBufferedOutputStream();

    wxOutputStream& Write( const void *buffer, size_t size );

    // Position functions
    wxFileOffset SeekO( wxFileOffset pos, wxSeekMode mode = wxFromStart );
    wxFileOffset TellO() const;
    bool IsSeekable() const { return m_parent_o_stream->IsSeekable(); }

    void Sync();
    bool Close();

    wxFileOffset GetLength() const;

    // the buffer given to the stream will be deleted by it
    void SetOutputStreamBuffer( wxStreamBuffer *buffer );
    wxStreamBuffer *GetOutputStreamBuffer() const { return m_o_streambuf; }
    wxDEPRECATED( wxStreamBuffer *OutputStreamBuffer() const );
  protected:
    virtual size_t OnSysWrite( const void *buffer, size_t bufsize );
    virtual wxFileOffset OnSysSeek( wxFileOffset seek, wxSeekMode mode );
    virtual wxFileOffset OnSysTell() const;

    wxStreamBuffer *m_o_streambuf;

    DECLARE_NO_COPY_CLASS( wxBufferedOutputStream )
};

inline wxStreamBase *wxStreamBuffer::Stream() { return m_stream; }
inline wxStreamBuffer *wxBufferedInputStream::InputStreamBuffer() const { return m_i_streambuf; }
inline wxStreamBuffer *wxBufferedOutputStream::OutputStreamBuffer() const { return m_o_streambuf; }

#endif // wxUSE_STREAMS

#endif // _WX_WXSTREAM_H__
